Protective Devices, Components Thereof, and Their Methods of Use

ABSTRACT

The present invention relates to a securing device configured to be worn by a person, characterised in that the securing device includes a locking mechanism that is configured to selectively secure a guard to the securing device at a plurality of positions relative to the securing device.

TECHNICAL FIELD

The present invention relates to protective devices, components therefore, and their methods of use.

BACKGROUND ART

Devices and apparatus to protect people and body parts from injury caused by impacts are known. Examples include helmets, shoulder pads, shin pads worn when playing sport, and hip protectors.

A common type of injury caused by an impact is a hip fracture, which is often the result of an impact to a person's greater trochanter. In fact, hip injuries are an area of particular importance in healthcare. Furthermore, as the population ages it is anticipated that hip injuries will become more common. Therefore, hip proctors are commercially important products.

Hip protector devices usually include a garment to be worn by a person, and a protective guard. The guard is often formed from an elastomeric material to absorb the impact, or a rigid material to shunt the force of an impact into soft tissue surrounding the hip joint.

Minns et al in Age and Aging 2007, 36140-144 have identified the importance of ensuring that hip protector guards are correctly positioned relative to the greater trochanter so as to provide effective protection against impacts. This is particularly relevant for hip protector devices utilising rigid guards. Incorrect positioning of the rigid guard could cause force to be transferred directly into the greater trochanter, actually increasing the occurrence of hip fractures.

In addition, guards are specifically configured so as to provide protection from an impact at certain orientations. Any inaccuracy in positioning a guard reduces its effectiveness.

The study of Minns et at also showed that the in use position for nine commonly used hip protectors was highly variable due to the hosiery with which they are used. Given the importance of having the guard correctly positioned this is a serious limitation of the prior art devices.

A further difficulty with preventing hip injuries is due to differences in people's anatomy. There is a natural variation across the population in greater trochanter size, location and orientation.

That variation is a result of differences in a number of anatomical dimensions, primarily the hip axis length and the neck/shaft angle of the femur. This natural variation hinders the efficacious use of hip protectors by making it harder to identify the correct position for a guard.

Existing hip protector garments do not account for this variation. Rather, available hip protectors are a “one size fits all” approach. The research of Minns et at discussed above confirms that this approach provides unsatisfactory results.

U.S. Pat. No. 6,408,446 to Carrington discloses garments to protect the hip area. The garment generally includes one or more pockets into which a protective guard may be inserted. The guard and the pocket are provided with complementary loop and hook fasteners that engage each other to hold the guard in position within the pocket.

The orientation of the loop and hook fasteners is such that the position of the guard within the pocket can be adjusted. However, the positioning of the guard within the pocket is variable and dependent on a wearer correctly identifying an optimum position for the guard. There is therefore a chance that the guard could be incorrectly positioned.

In addition, the loop and hook fasteners do not facilitate easily adjusting the position of the guard within the pocket.

Furthermore, the pads disclosed in the Carrington patent are made from high-density closed-cell foam. This acts as a simple impact absorber to prevent force of an impact being transferred into a greater trochanter. Those pads appear to simply wrap around the wearer's hip joint and do not have any specific shape or features to improve the level of protection. As a result, the garments and pads are likely bulky providing a less than desirable ascetic appearance. They may also provide unsatisfactory levels of protection.

Yet a further limitation of the existing hip protector devices is that these are cumbersome and uncomfortable. This can be a result of the guards being incorrectly positioned.

Alternatively, the guards may be oversized to compensate for variations in greater trochanter position and orientation. Accordingly, such devices have low adherence rates resulting in patients not being protected when a fall occurs.

The influence of patient comfort on adherence is an important consideration in designing a protective guard. This can be affected by factors including: guard weight, its feel against the body, and fit to an outer surface of the patient's leg. In addition, the guards are integrated into the undergarment and they cannot be taken off easily. They therefore have to allow the patient to lie on the guard during periods of rest, placing special demands on how far the guard protrudes from the body or its ability to compress.

Another factor relevant to improving adherence is the profile or appearance of a guard in use. This is particularly relevant for women who may be reluctant to wear bulky guards, which may protrude beyond their hip profile presenting an unflattering appearance.

Balancing the foregoing issues is important but the guard must still also be able to divert or reduce force of an impact. Currently available guards struggle to achieve this balance between impact attenuation, comfort and appearance.

MEDLOGICS manufactures a hip protector guard and markets this under the brand KPH Hip Protector. This product is an example of a guard which has high performance but potentially low adherence rates due to the fact it protrudes significantly from the body.

The KPH hip protector product is narrow and therefore has limited efficacy at reducing or minimising injury caused by an impact if incorrectly positioned. This limitation may actually be magnified due to the comfort issues discussed above, as a patient may incorrectly position the guard so as to make it more comfortable to wear. Therefore the product is not an effective solution to preventing hip injuries.

Another commercially available hip protector is sold under the brand name SAFEHIP. This product is generally effective when correctly positioned, but even small variances in positioning significantly reduce the guard's ability to minimise or reduce injury caused by an impact.

Yet a further limitation of the SAFEHIP product is due to it having an aperture overtop of the greater trochanter. Therefore the guard provides limited protection to the greater trochanter against a direct (point loaded) impacts against an object such as a table edge or a raised object on the floor.

Several commercially available products is that they are not tested to comply with two emerging testing protocols and standards: the SDMA (Surgical Dressings Manufacturers Association), and IHPRG (International Hip Protection Research Group). Both of the standards specify an impact energy which a hip protector guard is required to withstand, and how to measure the amount of force transferred to the greater trochanter.

In developing effective hip guards it is also important to take into consideration the different risk factors for each individual. These are influenced by considerations such as strength and hip joint and bone geometry, muscle degeneration, mobility, arthritis, osteoporosis, etc. Currently, producers of guards tend to produce a one type of guard on the assumption that people will wear these for the protection provided in all situations and contexts. However, if a person is still relatively fit and active they may be less willing to wear a heavier and/or more cumbersome guard and require a lower level of overall protection. However, those patients may be more likely to wear a lighter weight or more comfortable guard. In that case, increasing adherence rate during use would ensure that the guard's were present to protect the patient against a fall, and therefore decrease the incidence of hip injuries. Accordingly, having a range of products, which can be accurately matched to a patient's needs, would be of significant value.

It is an object of the present invention to address the forgoing failings of available hip protector devices, or to at least provide the public with a useful choice.

All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

Throughout this specification, the word “comprise”, or variations thereof such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

Further aspects and advantages of the present invention will become apparent from the ensuing description, which is given by way of example only.

DISCLOSURE OF THE INVENTION

According to one aspect of the present invention, there is provided a securing device configured to be worn by a person,

characterised in that the securing device includes a locking mechanism that is configured to selectively secure a guard to the securing device at a plurality of positions relative to the securing device.

According to another aspect of the present invention, there is provided a method of securing a guard to a securing device at a plurality of positions relative to the securing device,

the method including the steps of:

-   -   a) putting the securing device on a person;     -   b) selecting one of the plurality of positions at which to         secure the guard;     -   c) positioning the guard at the one of the plurality of         positions selected at step (b);         the method characterised by the step of:     -   d) using the locking mechanism to secure the guard in the         position selected at step (b).

According to another aspect of the present invention, there is provided a kit set of parts, including

a guard, a securing device configured to be worn by a person, wherein the securing device includes a locking mechanism configured to selectively secure the guard to the securing device at a plurality of positions relative to the securing device, instructions on how to use the locking mechanism and determine which of the plurality of positions at which to secure the guard to the securing device.

In a preferred embodiment, the present invention relates to a securing device, method, and kitset of parts for use in securing a guard at a position so as to protect a person's greater trochanter against an impact. Reference will be made herein as such.

Reference will be made herein to use of the securing device with a guard.

In a preferred embodiment the guard is a rigid body having a cavity and a foot portion which is configured to lie against a person's body. The cavity can receive the greater trochanter e.g. the rigid body overlies the person's greater trochanter and the cavity provides clearance between the rigid body and the person's greater trochanter.

In this embodiment, the rigid body shunts or transfers energy from an impact into the body area around the greater trochanter.

However, the forgoing should not be seen as limiting on the scope of the present invention. It is also envisaged that the guard may be an elastomeric material having a cavity and foot portion, or an impact absorbing pad without a cavity.

Throughout the present specification, reference to the term “securing device” should be understood as meaning a garment or component to be worn by a person. The securing device is therefore a protective device. In use the securing device can selectively hold a guard at one of a plurality of positions. This facilitates correct positioning of the guard with respect to the person's greater trochanter.

In a particularly preferred embodiment the securing device is a pair of underwear to be worn by a person. Reference will be made as such.

However, it is also envisaged that the securing device may be a holster, or belt and pocket assembly. Accordingly, the description herein should not be seen as limiting on the scope of the present invention.

In a preferred embodiment, the underwear includes at least one pocket.

The pocket is positioned so that in use it is laterally adjacent to, and overlies, a person's greater trochanter when the underwear is being worn.

Further aspects of the pockets will be discussed below and should become clearer from the following description.

However, the forgoing should not be seen as limiting on the scope of the present invention. It is also envisaged that the securing device may not include a pocket. Rather, in such embodiments the locking mechanism is configured to selectively secure the guard at one of the plurality of positions by attaching the guard to the outer surface of the securing device.

Throughout the present specification, reference to the term “locking mechanism” should be understood as meaning components to selectively secure the guard at one of a plurality of positions.

In a particularly preferred embodiment, the locking mechanism is a plurality of fasteners that are configured to alter the dimensions of the pocket e.g. engaging a pair of fasteners decreases the pocket's length. Accordingly, the pocket can hold the guard at one of several positions with respect to the securing device. It is also envisaged that the edges of the pocket may define a position at which to hold a guard e.g. the guard bears on the bottom edge of the pocket, and the pocket holds the guard in a position relative to the person's greater trochanter.

The inventors have found that alternate dimensions of the pocket are a particularly beneficial way of securing the guard in the optimum position. For instance, there is less variability in positioning of the guard and therefore higher probability that the guard will be held in the optimum position.

Furthermore, in this embodiment the pocket may provide a more secure way to secure the guard in the optimum position. Accordingly, the present invention addresses limitations of some of the prior art devices.

However, alternative embodiments are envisaged. For instance the locking mechanism may be a plurality of complementary fasteners. A male or female fastener is secured on the guard, and a plurality of the complementary male or female fasteners are secured on the underwear. Each of the fasteners on the underwear corresponds to one position at which the guard is to be held. In use, the desired position is determined (as is discussed below) and the appropriate pair of fasteners is used to secure the guard at the position.

Other embodiments for the fasteners and locking mechanism are envisaged including VELCRO, buttons, hooks, eyelet fasteners, and adhesives. Accordingly, the forgoing should not be seen as limiting.

Throughout the present specification, reference will be made to the term “plurality of positions”. This should be understood as meaning two or more positions at which a guard may be secured so that the guard can protect a person's greater trochanter against an impact.

In a particularly preferred embodiment, the plurality of positions are spaced apart in the range of 70 mm-100 mm.

In a particularly preferred embodiment, the plurality of positions are spaced apart within the range of substantially 90 mm. For instance, the locking mechanism may be configured to secure the guard in a number of positions spaced vertically from each other, and also a number of positions spaced laterally (substantially horizontally) from each other.

Alternatively, the plurality of positions may be both vertically and laterally spaced apart. E.g. the locking mechanism can hold the guard in a plurality of positions that vary substantially vertically and/or substantially horizontally when the underwear is being worn by a person.

However, the forgoing should not be seen as limiting on the scope of the present invention. For instance, the plurality of positions may be spaced apart in a range of less than 70 mm.

In a particularly preferred embodiment, the plurality of positions correspond to an “optimum position” as will be discussed below.

Throughout the present specification reference to the term “optimum position” should be understood as meaning a position relative to a person's greater trochanter to maximise the guard's ability to protect the greater trochanter from an impact.

The optimum position corresponds to that in which the guard is centered over top of the person's greater trochanter. Therefore the guard's footprint abuts the person around the greater trochanter. Accordingly, this maximizes the guard's ability to substantially shunt or redirect impact into the soft tissue surrounding the greater trochanter, and thereby prevent an object substantially contacting the greater trochanter.

The optimum position varies from person to person according to natural differences in hip joint anatomy.

In addition, the optimum position may differ due to the parameters and type of guards used with the present invention.

However, the locking mechanism is beneficial as it facilitates maximising the guard's protective benefits. In addition, it enables the present inventions to be easily used with a broad cross section of the population.

In a preferred embodiment, a kit set according to the present invention includes instructions on how to determine the optimum position.

The instructions will vary according to the guard used with the present invention. However in a preferred embodiment the instructions teach any or all of the following steps:

-   -   (a) stand in an upright position;     -   (b) form a right angle between your thumb and middle finger;     -   (c) lie your thumb on the Iliac crest of the pelvis (boney         protrusion at the top of the hip) with the palm of your hand         lying against the side of the leg;     -   (d) identify the hip bone (greater trochanter) by noting the         boney protrusion sitting underneath approximately the end of         your middle finger;     -   (e) position the guard so as to lie overtop of the greater         trochanter;     -   (f) mark the securing device so as to record the optimum         position and the appropriate configuration of the locking         mechanism.

However, the forgoing should not be seen as limiting. It is possible that the instructions included in the kitset of parts may include other steps or methods of determining the position of person's greater trochanter.

It should be appreciated that the present invention has a number of advantages over the prior art.

The locking mechanism provides a cost effective and simple way to secure a guard in an optimum position so as to maximise the protective benefits which may be provided by the guard.

In addition, the use of the locking mechanism enables customised guard positioning yet requires a minimal range and stock of securing devices (underwear). Accordingly, it is possible for a manufacturer of securing devices and guards to streamline their product offerings and inventory.

Furthermore, the present invention may improve adherence rates for use of protective devices. This is a direct result of the guards being better positioned and therefore more comfortable. Accordingly this can reduce the incidence of hip fractures caused by impact to the greater trochanter.

Yet another advantage of the present invention may be that the locking mechanism and method of determining greater trochanter position are easy to use. Therefore, the inventions do not require complex diagnosis to identify correct guard position. Rather, the method can be implemented by medical support staff, careers, or even patients themselves.

According to one aspect of the present invention there is provided a guard, including

a body, a foot portion to abut a person's body, a cavity in the body, wherein in use the guard is configured to be positioned adjacent to a person's body so that the cavity overlies the person's greater trochanter, characterised in that the cavity has a clearance area of at least 3660 mm².

According to another aspect of the present invention, there is provided a guard, including

a body, a foot portion to abut a person's body, wherein the foot portion has a pair of spaced apart points that in use are on distal sides of the person's greater trochanter, characterised in that, the spaced apart points both lie on a cylindrical plane having a radius in the range of 70 mm to 120 mm.

According to one aspect of the present invention, there is provided a guard, including

a body against which an impact may occur, a foot portion to abut a person's body, characterised in that the guard includes a transitional section between the foot portion and the body to increase the rigidity of the body.

According to another aspect of the present invention, there is provided a guard, including

a main body made from a compressible material, characterised in that the compressible material has:

-   -   a tensile strength in the range of 15-84 KPa;     -   a hardness in the range of 10-85 JIS C.

According to another aspect of the present invention, there is provided a guard, including

a body made from a rigid material, characterised in that the rigid material has:

-   -   a tensile strength in the range of 35-200 MPa;     -   an elastic modulus in the range of 750-8500 Mpa.

According to another aspect of the present invention, there is provided a guard to protect a body part of a person, including

a body, a cavity in the body, a foot print configured to abut the person's body part when the guard is in use, characterised in that the footprint has a shape that corresponds to the curvature of the body around the body part to be protected.

In a particularly preferred embodiment, the guards according to the present invention protect a person's greater trochanter from an impact so as to reduce incidence of hip fractures or other injuries caused by an impact. Accordingly, reference throughout the present specification will be made to the guards as protecting a person's greater trochanter.

However, the forgoing should not be seen as limiting on the scope of the present invention and the guards can also be used to protect other body parts such as ankles, knees, wrists and shoulders.

Throughout the present specification aspects of the present invention will be described with reference to a person's greater trochanter in a “reference position” which is when a person wearing the guard is standing. However, this should not be seen as limiting on the scope of the present invention. References are merely to clarify the relative orientation and/or interaction of the different components of the present invention.

Throughout the present specification, reference to the term “guard” should be understood as meaning a device to prevent or reduce hip injury caused by an impact to the greater trochanter.

In one embodiment, the guard includes a rigid component to transfer force (or substantially transfer force) into tissue surrounding a person's greater trochanter. In this embodiment, the guard substantially prevents force being transferred to the person's greater trochanter.

In an alternate embodiment the guard includes a body or component formed from a compressible material. In this embodiment, the compressible material absorbs the force of an impact so as to minimise or prevent this being transferred to the person's greater trochanter.

These aspects of the present inventions should become clearer from the following description. The inventors have discovered that various properties of the materials used to manufacture the guards according to the present invention are important. Accordingly, ranges for different aspects of the materials will first be described before moving onto preferred embodiments of the material.

In preferred embodiments, guards according to the present invention include bodies formed from materials having:

-   -   an elastic modulus in the range of 750-8500 MPa, and more         preferably 5500-8500 MPa;     -   a tensile strength in the range of 1500-84 KPa, and more         preferably 105-150 MPa;     -   a hardness in the range of 10-85 JIS C, and more preferably a         combination of at least two materials having a hardness of 25         JIS C and 65 JIS C.

The terms elastic modulus, tensile strength, and hardness are as should be understood by one skilled in the art.

These properties of the materials for use in manufacturing guards according to the present invention should become clearer from the following description.

In preferred embodiments the bodies are made from a thermoplastic or thermoset polymer.

In a preferred embodiment, a rigid component of the body is formed from nylon containing reinforcing. The reinforcing may be glass fibre in a concentration of between 0-40% w/w.

In a particularly preferred embodiment, the rigid component is formed from nylon containing 30% w/w glass fibre reinforcing.

However, the forgoing should not be seen as limiting, and other materials are envisaged including polypropylene, acetyl, nylon, and/or polycarbonate.

In a preferred embodiment, a compressible component of the present invention is formed from a lamination of two or more materials. These materials preferably differ in their mechanical properties such as density, tensile strengths, elastic modulus etc.

In a particularly preferred embodiment, a compressible component is formed from a lamination of polyethylene foam with a density of substantially 140 kgm³ and polyethylene foam with a density of substantially 40 kgm³.

Alternatively the compressible component is formed from one or more of ethyl vinyl acetate (EVA), polyethylene foam or any other foam, elastic or elastomeric material.

However, the foregoing should not be seen as limiting on the scope of the present invention as the rigid component and compressible component may be made from other materials.

The inventors have found that using a combination of different compressible materials helps to improve the performance of the guards. It is believed that the comparatively denser material is able to transfer some material into areas surrounding the greater trochanter. Accordingly, this means that the guard does not need to absorb as much energy so as to prevent a hip injury. The guard in effect is acting in a similar manner to a guard described herein using a rigid body. However, the use of a comparatively less dense material helps to improve the guard's “feel” against a person's body. This may improve adherence rates.

Throughout the present specification, reference to the term “foot portion” should be understood as meaning two or more points that in use abut a person's body.

In a preferred embodiment the at least two points are a pair of laterally spaced apart points on distal sides of the person's greater trochanter.

In the preferred embodiment, the pair of lateral points both lie on a cylindrical plane having a radius in the range of 70 mm to 113 mm.

In a particularly preferred embodiment the pair of lateral points both lie on a cylindrical plane having a radius of substantially 85 mm.

This aspect of the present invention should become clearer from the following description.

In a preferred embodiment, the foot portion also includes at least an upper point and/or lower point.

Throughout the present specification, reference to the term “upper point” should be understood as meaning a point of the footprint which in the reference position is above the greater trochanter.

Throughout the present specification, reference to the term “lower point” should be understood as meaning a point of the footprint which in the reference is below the greater trochanter.

In a preferred embodiment, the upper and lower points of the foot portion also lie on the same cylindrical plane as the pair of lateral points (as is discussed above). However, the upper and lower points lie on different circular sections of the cylindrical plane to the lateral points e.g. the upper and lower points are spaced apart along the length of the cylindrical plane.

In a particularly preferred embodiment, the upper and lower points also both lie on a plane that curves about a substantially horizontal axis and has a radius in the range of 200 mm to 350 mm.

In a particularly preferred embodiment the upper and lower points also both lie on a plane that about a horizontal axis has a radius of substantially 250 mm.

However, the forgoing should not be seen as limiting on the scope of the present invention and it is also envisaged that the foot print may have pairs of points that lie on different planes, or planes having different radii curvatures.

In a preferred embodiment, the shape of the foot portion is determined by connecting each of the pair of laterally spaced points to the upper and lower points, using smooth curves that follow the cylindrical plane on which the lateral points and upper and lower points all lie.

The inventors have found that this shape for the foot portion provides the guard with an ergonomic fit, which mimics the shape of a significant portion of the population's hip joint anatomy. The guard may therefore better conform to a patient's leg shape. Accordingly the guards according to the present invention may be more comfortable to wear than any or all or the prior art guards, and therefore improve adherence of use.

The shape of foot portion is also beneficial as it facilitates provision of the clearance area. This ensures that a guard according to present invention does not contact a person's greater trochanter in use. Accordingly, this may be beneficial in reducing or preventing transfer of force of an impact into the greater trochanter. For instance, in the embodiment where the rigid guard includes a rigid body or component, the footprint helps to transfer the force of the impact into the tissue surrounding the greater trochanter.

Throughout the present specification, reference to the term “clearance area” should be understood as meaning the minimum area of an opening into the cavity.

In a preferred embodiment, the guards have a clearance area in the range of substantially 3000 mm² to 8500 mm².

In a particularly preferred embodiment, a guard made from a rigid material has a clearance area of 8248 mm² and a guard having made from a compressbile material has a clearance area of 3661 mm².

Ensuring that the guards have the clearance area discussed herein is important in ensuring that the guards can effectively reduce or minimise injuries caused by an impact. The inventors have identified that with the minimum clearance area the guards according to the present invention can provide the required force attenuation to reduce or eliminate injuries caused by an impact.

Furthermore, the minimum clearance area is particularly beneficial in ensuring that guards according to the present invention are effective were an impact to incur “off centre” of the guard.

The minimum clearance area may also help to improve the effectiveness of guards according to the present invention were these to be positioned incorrectly relative to a person's great trochanter. E.g. the guards have an increased ability to prevent or minimise transfer of force to greater trochanter when used in different positions.

These aspects of the present invention should become clearer from the following discussion.

In a preferred embodiment, the clearance area lies on the same cylindrical plane as the pair of laterally spaced apart points of the footprint (as discussed above).

However, the forgoing should not be seen as limiting as the clearance area could also lie on a flat plane.

In a preferred embodiment, the clearance area has a minimum length in the range of 80 mm to 125 mm.

In a particularly preferred embodiment the clearance area has a minimum length of substantially 84 mm.

This range of lengths for the clearance area helps to account for natural variations in the location, size, or orientation of greater trochanter across the population.

In addition, this range of lengths for the clearance area helps to ensure the guards are effective in minimising or reducing transmission of force into the greater trochanter were the guard to be incorrectly positioned.

In a preferred embodiment, the clearance area has a width in the range of 46 mm to 90 mm.

In an embodiment where the guard includes a component formed from a compressible material, the clearance area has a width of substantially 55 mm.

In an alternative embodiment, where the guard includes a body made from a rigid material, the clearance area has a width of substantially 82 mm.

The widths for the clearance area described herein are particularly beneficial in ensuring that the guards are capable of performing their intended functions. For instance, having a clearance area with a width of substantially 55 mm ensures that the guard has a body of material sufficient to absorb the energy of any impact and prevent that being transferred to the greater trochanter.

In contrast, having a clearance area with a width of substantially 82 mm enables the guard to shunt the force of an impact into areas surrounding the greater trochanter. These aspects and benefits should become clearer from the following description.

In addition guards made from compressible materials do not have sufficient structural integrity to withstand force of an impact if the clearance area is large. Accordingly, the use of specific clearance areas is important.

However, the foregoing should not be seen as limiting on the scope of the present invention as it s also envisaged that the guards may have clearance areas having other lengths.

Throughout the present specification reference to the term “clearance distance” should be understood as meaning a minimum distance between the clearance area and an inner wall of the cavity.

In a preferred embodiment, the guards according to the present invention have a clearance distance in the range of 10.1 mm to 14.9 mm.

In a particularly preferred embodiment, guards according to the present inventions have a clearance distance of substantially 12.5 mm.

However, the foregoing should not be seen as limiting on the scope of the present invention. It is also envisaged that the guards may have other clearance distances than those described herein. What is important is that the clearance distance is sufficient to ensure that any deformation of the guard on occurrence of an impact does not result in the impact being transferred to the greater trochanter. The inventors have found that having clearance distances within the ranges described herein helps to ensure that the guards prevent or minimise transmission of an impact into the greater trochanter. Accordingly, the described clearance distances are particularly important in ensuring that the guards of the present inventions can perform their desired purpose.

Throughout the present specification reference to the term “transitional section” should be understood as meaning a section of the guard between the foot portion and the contact surface which increases the rigidity of the contact surface.

In a preferred embodiment, the transitional section is a reinforcing section. The section may have the same, greater, or less thickness than other parts of the guard. However, what the transitional section does is to increase the rigidity of the contact surface so that it deforms less on occurrence of an impact than were the transitional section not used in the guard.

The aspects of the transitional section will vary according to a number of variables in the guards manufacture or configuration. These may include materials from which the guard is made, the thickness of materials, the shape of the contact surface, the size of the cavity in the guard, the clearance area and clearance distance etc.

In a particularly preferred embodiment, a transitional section is defined by one or more joints. A first joint may be between the transitional section and the contact surface, and a second joint may be between the foot portion and the transitional section.

In this embodiment, the transitional section provides a change in angle and/or shape of the contact surface. This increases the rigidity of the contact surface.

This aspect of the present invention should become clearer from the following description.

However, the foregoing should not be seen as limiting on the scope of the present invention. It is also envisaged that the transitional section could be a region of material thicker than the contact surface, and which has an outer surface with the same curvature as the contact surface so as to provide a continuous outer surface for the guard

In a preferred embodiment, the angle between the contact surface and transitional section is determined with reference to an imaginary plane defined by connecting two points of the transitional section at the point between the transitional section and the body.

The imaginary plane is graphically represented in the Figures and discussed further in the Best Modes section of this specification.

In a preferred embodiment, the angle between the plane and the transitional section is in the range of 5 degrees-30 degrees.

In a particularly preferred embodiment the plane is 11 degrees.

This aspect of the present invention should become clearer form the following description.

In preferred embodiment, the transitional section has a height in the range of 3 mm to 15 mm.

In a particularly preferred embodiment, the transitional section has a height of substantially 7.1 mm.

The inventors have discovered that the use of the transitional section significantly increases the present invention's ability to transfer force into tissue surrounding the greater trochanter. The transitional section also facilitates a guard having a lower profile (greater radius curvature) contact surface, and manufacturing of these from thinner, lighter-weight, or less dense materials. This is because the guard does not deform on impact to the contact surface, or deforms less than would otherwise occur.

The transitional section is also beneficial as it provides greater separation between an internal wall of the cavity and the clearance area e.g. the transitional section increases or helps to provide the clearance distance. Accordingly, any deformation of the contact surface is less likely to cause contact at greater trochanter.

These aspects of the present invention should become clearer from the following description.

Throughout the specification reference to the term “contact surface” should be understood as meaning a surface of the body against which an impact may occur.

The contact surface may be a continuous piece of material extending across the width and/or length of the guard.

Alternatively, the contact surface may be discontinuous, e.g. there is a gap or opening the contact surface. Regardless, the contact surface provides a plurality of points at which an impact may occur. Accordingly, the forgoing should not be seen as limiting.

In a preferred embodiment the shape of contact surface is a complex combination of two or more curvatures.

In a particularly preferred embodiment the contact surface has a first curvature around a substantially horizontal axis and a second curvature around substantially vertical axis. In this embodiment, the:

-   -   First curvature has a radius in the range of 70 mm-90 mm, and         preferably substantially 75 mm; and     -   Second curvature has a radius in the range of 110 mm-200 mm, and         preferably substantially 170 mm.

However, the foregoing should not be seen as limiting on the scope of the present invention as the contact surface may also have other shapes and configurations.

The inventors have found that the ranges for the curvatures of the contact surface are particular beneficial for a number of reasons. Firstly, the curvatures provide the guards with a desirable profile when worn. That is, the guards are slim line and unobtrusive. They are therefore more likely to be worn, especially by women who may be particularly self-conscious of protrusions on or around their hips.

Secondly, the curvatures help to provide the guards with a cavity large enough to provide the necessary clearance area and clearance distances (as are discussed above), Accordingly, the curvatures are important in ensuring that the guards can reduce or minimise transmission of force of an impact into the greater trochanter so as to minimise hip injury.

Thirdly, the curvatures are linked to the shape of the footprint. Therefore, the shape of the contact surface is linked to and influenced by the way that the footprint confirms to a patient's body. It can therefore be seen that this is a unique interaction between the different components of the guard.

In a preferred embodiment, the guards according to the present invention have a weight in the range of 30 g-70 g.

In a particularly preferred embodiment, a guard including a compressible component has a weight of substantially 40 g.

In an alternately preferred embodiment, a guard having a rigid component has a weight of substantially 62 g. This weight is provided by the rigid component itself, and/or other components of the guard. For instance, in one embodiment it is possible that the guard includes a liner, the weight of which contributes to the total weight of the guard. E.g. the rigid component has a weight of substantially 55 g and the liner has a weight of substantially 7 g.

The inventors have found that guards having weights within the above described ranges is particularly important in improving the performance of the guards.

Furthermore, it is important in selecting materials for use and manufacturing guards to consider what the final weight of the guards will be.

Certain types of materials may have mechanical properties such as elastic modulus, tensile strength, and hardness which make them well suited for use in protective guards. However, guards made using certain materials may have a significant weight to achieve a desired performance for guard. Accordingly, accurately matching the materials from which the guards are made, their mechanical properties, and the resulting weights of the guards, is particularly important.

It should be appreciated from the foregoing discussion that the present inventions provide a number of advantages. These include that these guards:

-   -   Can be better matched to a patient's personal risk profile and         may therefore improve adherence of patient use.     -   Are more comfortable to wear and therefore may improve adherence         of patient use.     -   May be manufactured from lighter weight materials.     -   Are smaller and less bulky than the available guards.         Accordingly, in use the guards have a lower profile on a         patient's body and may therefore improve patient adherence         during use.     -   Can better account for natural variations in greater trochanter         position across the population, and therefore may reduce         incidence of injury caused by impacts.     -   Are more efficient at minimising or preventing transfer of         impact into a patient's greater trochanter and therefore may         reduce the incidence of injuries caused by impacts.

There is a unique interaction of two or more of the inventions described herein to improve the efficiency of guards. For instance, the transitional section increase rigidity of contact surface and therefore prevent or limits it's deformation. This in turn may prevent or reduce the transmission of an impact into a person's greater trochanter. In addition, transitional section also provides assists in providing minimum clearance distance.

Likewise, the shape of foot portion is related to minimum clearance area and therefore helps to ensure that the guard does not touch a person's greater trochanter. It therefore helps to prevent or reduce transmission of force of an impact in the greater trochanter. However, the shape of the footprint is also ergonomically designed so as to improve the comfort of the guard when worn. Accordingly, the footprint is important in improving adherence.

In respect of a guard including a compressible component, there is also a unique interaction of different components. For instance, the shape of the contact surface is important in providing the guard with a lower profile appearance when worn. That therefore contributes to increasing adherence rates. However, the shape of the contact surface is also important in ensuring that the guard has sufficient material to be able to absorb force of an impact and thereby prevent it being transferred into greater trochanter.

The inventors have identified that each of the inventions disclosed herein are important in their own right. However, the sum of two or more of each of the innovations is particularly beneficial in improving the performance of the guards. There is a synergistic effect from the unique interaction of the different inventions.

In addition, the guards described herein may be particularly beneficial for use with the securing device. For instance, the use of the locking mechanism of the securing device may enable use of guards which are more compact, lighter weight, or narrower than the prior art guards. These components together could increase the protection provided against impact or lead to higher adherence rates, thereby decreasing injuries.

BRIEF DESCRIPTION OF DRAWINGS

Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

FIG. 1 a is a front cross sectional view showing hip joint anatomy and anatomical references;

FIG. 1 b is a front view showing parameters effecting greater trochanter location;

FIG. 1 c is a top view of FIG. 1 b;

FIG. 2 is a front view of a securing device for men according to the present invention;

FIG. 3 is a top perspective view of a securing device for women according to the present invention;

FIG. 4 is a side view showing how to determine greater trochanter location;

FIG. 5 a-c are schematics showing use of the securing device and locking mechanism according to the present invention;

FIG. 6 is a side view showing a guard in three representative positions relative to the securing device;

FIG. 7 a is a cross sectional view showing aspects of the present inventions with reference to hip joint anatomy;

FIG. 7 b is a bottom view of a guard showing aspects of the present invention;

FIG. 8 a is first perspective view of a guard according to a first embodiment of the present invention;

FIG. 8 b is a cross sectional view through section B-B in FIG. 8 a;

FIG. 8 c is an exploded view of a guard according to one embodiment of the present invention;

FIG. 8 d is a top view of FIG. 8 a;

FIG. 8 e is an end view of FIG. 8 a;

FIG. 9 a is a first perspective view of a guard according to a first embodiment of the present invention;

FIG. 9 b is an alternate perspective view of FIG. 9 a;

FIG. 9 c is a cross sectional view through section A-A in FIGS. 9 a and 9 b;

FIG. 9 d is an end view of FIG. 97;

FIG. 10 a is a perspective view showing the footprint of a guard according to one aspect of the present invention;

FIG. 10 b is an end on view of FIG. 10 a;

FIG. 11 a is a front schematic view showing a guard according to one aspect of the present invention in use;

FIG. 11 b is a plan view of FIG. 11 a.

BEST MODES FOR CARRYING OUT THE INVENTION

Aspects of the present invention are best understood with reference to anatomy of hip joints and general variations in same. Accordingly, hip anatomy is discussed before a detailed description of how the present invention solves problems arriving from natural variations in hip anatomy.

Hip Anatomy

Referring to FIG. 1 a front cross sectional view of a hip joint, generally indicated as (1). The hip joint (1) is the ball and socket interaction of a person's femur (2) and pelvis (3). The femur (2) has a femoral head (4) which sits within socket indicated generally as (5) in pelvis (3).

Femoral neck shaft (6) extends from femoral head (4) to meet femur (2). Greater trochanter (7) is a bony protrusion which extends from the intersection of femur (2) and femoral neck shaft (6).

Most commonly, impacts occur at the outer most edge (7 b) of greater trochanter (7) as this is the furthermost point from hip joint (1). Accordingly, reference herein will be made to greater trochanter with reference to point (7 b).

There is considerable variation in the location and orientation of greater trochanter (7 b) across the population. This is a result of the sum of minor differences in the size, girth, length, and orientation (angles between) between each of the body parts forming the hip joint.

Hip joint anatomy varies naturally across the population. For ease of reference common geometric dimensions are shown in FIG. 1 a using the labels in Table 1:

TABLE 1 Anatomical Dimension 8 Femoral axis length 9 Hip axis length (HAL) 10 Horizontal offset 11 Gluteal tuberosity 12 Neck shaft angle 13 Femur diameter above less trochanter 14 Inter-hip distance 15 Trochanter width 16 Pelvic width

The inventors have identified five key parameters that affect greater trochanter position between people. These parameters and values for them are summarised in Table 2:

TABLE 2 Reference on Condition FIGS. 1b and 1c Value* (mm) Greatest distance the greater 17 Extreme 48.7 trochanter protrudes from the outside Reasonable of the vertical femur bone 15** Lowest greater trochanter point from 18 115.5 pelvis end of HAL Highest greater trochanter point from 19 39.9 pelvis end of HAL Most forward greater trochanter point  20a 7.3 from pelvis end of HAL Most backward greater trochanter  20b 18.9 point from pelvis end of HAL

Of these parameters, hip axis length (9) and neck shaft angle (12) are considered to be the most significant influence on location of greater trochanter (7 b).

It can be seen from Table 2 above that location of greater trochanter (7 b) varies vertically in the range of 85 mm. E.g. the difference between lowest and highest point of greater trochanter from the end of hip axis length.

FIGS. 1 a-c show graphically hip anatomy and the factors which affect variations in location of greater trochanter (7 b).

It is very important that protective devices and the securing devices used with them take into account variation in location of greater trochanter (7 b). The present inventions ability to account for variation in location of greater trochanter should become clearer from the following description.

Securing Device

Referring now to FIGS. 2, 3 & 4.

According to the present invention, there is provided a securing device (22) in the form of underwear. The underwear (22) is configured to selectively hold a guard (23) at one of a plurality of positions relative to a person (24) and therefore hip joint (1).

The guard (23) may be any form of guard as should be known to one skilled in the art.

Alternatively, the guard (23) may be a guard as is substantially described herein with reference to FIGS. 7-11.

The underwear (22) has a pair of pockets (25). Each pocket (25) is orientated so as to lie generally and substantially parallel to a person's femur (2) when standing.

Each pocket (25) has two pairs of fasteners (26 a, 26 b) spaced apart along length of pocket.

Fasteners (26 a, 26 b) are above bottom edge (27) of pocket (25).

Accordingly, fasteners (26 a, 26 b) and pocket (25) provide a range of 75.6 mm at which a guard (23) can be secured.

Each pair of fasteners (26 a and 26 b) and bottom edge (27) corresponds to a position in which a guard could be held relative to a person's greater trochanter (7 b). This will be expanded upon below.

A spacer material (not shown) may be underwear (22) so as to be positioned between the fasteners (26 a, 26 b) on the person's body. The spacer may be a soft material having some elastomeric properties e.g. felt or cotton. In-use, the spacer material provides cushioning between the fasteners (26 a, 26 b) and the person's body. This may prevent the development of pressure sores or irritation when the underwear (22) is worn by a person.

Guards (23) in the form of a rigid body, have a footprint (28) and a cavity (not shown).

The guards are able to be inserted into pockets (25).

In use, footprint (28) abuts the outer surface of person's leg around greater trochanter (7 b).

The present invention includes instructions on how to identify an optimum position for guard (23) so as to maximise its ability to protect greater trochanter (7 b) from an impact.

The instructions teach a person to identify an optimum position for guard (23). The method involves a person performing the steps of:

-   -   (a) standing in an upright position;     -   (b) to identify the Iliac crest of the pelvis form a right angle         between your thumb and first finger;     -   (c) lie your thumb on the Iliac crest with the palm of your hand         (29) lying to the side of the leg;     -   (d) the hip bone or greater trochanter (7 b) is the boney         protrusion sitting underneath approximately the end of your         middle fingers;     -   (e) position the guard (23) to lie overtop of greater trochanter         (7 b) so that greater trochanter (7 b) sits within cavity (29).

This is schematically shown in FIGS. 5 a-c

A referencing system (30) is provided on underwear (22). This allows a person to note which fasteners (26 a, 26 b) should be engaged to hold guards (23) in the optimum position. This is beneficial as it provides a reference for the optimum position should the guards (23) be removed from the underwear (22) to facilitate its washing or other care.

In addition, the referencing system (30) facilitates one pair of guards (23) being easily used with multiple pairs of underwear (22) thereby minimising costs for patients or other health care funders.

Securing Device in Use

Referring now to FIGS. 5 a-c.

A person puts on the underwear (22) and performs the method described above so as to identify location of greater trochanter (7 b).

The guard (23) is then positioned so that cavity (not shown) is centered overtop of greater trochanter (7 b).

Fasteners (26 a, 26 b) are engaged or disengaged to change length of pocket (25). This reduces the dimensions of (shortens) pocket (25).

Guard (23) is inserted into pocket (25) and slid along the length of pocket so that bottom edges of guard (23) sit against a fastener (26 a or 26 b), or bottom edge (27) of pocket (25).

Pocket (25) prevents guard (23) moving laterally. This is due to the width of pocket (25).

The process above is repeated for the person's other greater trochanter (7 b) on other side of pelvis using another pocket (25) and another guard (23) in underwear (22).

It should be appreciated from the forgoing description that the present inventions have a number of advantages over the prior art.

Importantly, the underwear according to the present invention facilitates holding of guards at an optimum position so as to maximise the guard's protective benefits. The optimum position can be easily selected according to a patient's individual requirements. Accordingly, the present inventions can be used across the population so as to account for natural variation in location/orientation of greater trochanter.

In addition, the present inventions can be used with different types of guards having generally similar shapes. Therefore, they facilitate better matching of a protective component to a person's individual requirements.

Yet a further advantage of the present inventions is that the guards are interchangeable. An extension of this feature is that underwear can be easily replaced when worn out to facilitate use of one pair of guards with multiple pairs of underwear. Therefore, the present inventions may reduce the total costs of providing protective devices to patients.

Other advantages include that:

-   -   The locking mechanism can account for differences in a patient's         size such as thigh curvature and muscle mass, or waist         circumference, which may have otherwise influenced a securing         device's ability to hold a guard in an optimum position.     -   It is also possible that the securing device will account for         personal preferences in how people wear underwear which may         affect guard position.     -   The method of identifying greater trochanter location is easily         understandable and repeatable.     -   The securing device allows use of smaller, less bulky guards and         therefore may increase adherence rates.

Rigid Guard

Referring now to FIGS. 8 a-e which show a first embodiment of a guard (36) to protect a person's greater trochanter (7 b). Guard (36) includes a rigid body (37) made of nylon containing 30% w/w glass reinforcing.

Referring now to FIGS. 10 a and 10 b

The rigid body (37) has a foot portion (38) having a complex three-dimensional shape. The foot portion (38) has a pair of laterally spaced apart points (39, 40) that in use are on either side of greater trochanter (7 b). The points (39, 40) both lie on a cylindrical plane (43) which has a radius of substantially 85 mm

The foot portion (38) also has an upper point (41) and a lower point (42). The upper and lower points (41, 42) lie on the same plane (43 a) as lateral points (39, 40).

The upper and lower points (41, 42) also both lie on a cylindrical plane (43 b) that has a radius of substantially 170 mm. In the reference position the upper and lower points (41, 42) are respectively above and below greater trochanter (7 b).

The foot portion (38) extends around the entire perimeter of rigid body (37).

Rigid body (37) has a continuous contact surface indicated generally by (44). The shape of contact surface (44) is a complex combination of curves. A first curvature is around a substantially vertical axis when the guard is in the reference position. The first curvature has a radius of substantially 75 mm. A second curvature is around a substantially horizontal axis when the guard is in the reference position. The second curvature has a radius of substantially 170 mm.

A transitional section (45) connects foot portion (38) and contact surface (44). The transitional section (45) has a height indicated by line (46) of 71 mm.

Point (47 a) indicates the joint between contact surface (44) and transitional section (45). Further aspects of the transitional section (45) and its relationship to the contact surface (44) can be understood with reference to an imaginary plane (46) defined by connecting any two separated points (47 a, 47 b) of the junction between transitional section (45) and contact surface (44).

The angle (x) between plane (46) and outside surface (48) of transitional section (44) is approximately 11°.

A cavity (49) is defined by an aperture generally indicated and an inner wall (51). The cavity (49) has a teardrop shape with a maximum length (51) of 84 mm and a maximum width (52) of 82 mm.

A liner (53) made from ethyl vinyl acetate 30 is attached to rigid body (37).

The liner (53) has a footprint (54), transitional section (55), and curved surface (56) generally corresponding to the footprint (38), transitional section (45), and contact surface (44). This allows liner (53) to tightly fit into cavity (49).

The liner (53) makes the guard (36) more appealing to users as it provides a soft layer, which in use will lie against a person's body. This may help to improve adherence rates by making the guard (36) more comfortable during use.

The liner (53) may also absorb some force of an impact and therefore help to improve performance of guard (36).

Foam Guard

Referring now to FIGS. 9 a-9 d which show an alternate embodiment of a guard (28) to protect a person's greater trochanter (7 b).

The guard (28) includes a body (29) made from a laminate of Polyethylene Foams (PE) with an outer layer having density substantially 140 kgm³ and an inner layer having a density of substantially 40 kgm³.

The outer layer has a thickness in the range of 1.5 mm-6 mm across the guard's dimensions. The inner layer has a thickness in the range of 4 mm-20 mm across the dimensions of the guard (28).

The outer layer provides a contact surface (30) against which an impact may occur. The shape of contact surface (30) is a complex combination of curves. In general, contact surface (30) has a first curvature around a substantially vertical axis (31) and a second curvature around a substantially horizontal axis (32). The first curvature has a radius of substantially 75 mm. The second curvature has a radius of substantially 170 mm.

A cavity (33) is defined by an aperture and an inner wall (34) of body (27). The cavity (34) has a teardrop shape.

The body (29) has a foot portion (35) that extends around perimeter of cavity (33).

In use, the body (29) lies against person so that foot portion (35) abuts surface of person's leg around greater trochanter (7 b).

The foot portion (35) has a complex three dimensional shape that is substantially the same as foot portion (38) discussed above for guard (36). Therefore foot portion (35) is described herein with reference to FIGS. 4 a and 4 b using similar reference numerals to those used to describe foot portion (38).

The foot portion (28) has a pair of spaced apart points (39, 40) that both lie on a cylindrical plane (43) that has a radius of 85 mm. In use, the points (39, 40) are on distal sides of greater trochanter (7 b)

The foot portion (28) has an upper point (41) and a lower point (42) that in the reference position are respectively above and below greater trochanter (7 b).

The upper and lower points (39, 40) also both lie on cylindrical plane (43). The shape of footprint (28) is created by connecting the points (39-42) e.g. point (41) is connected to points (39, 40) by following cylindrical plane (43), and lateral points (39, 40) are connected to point (42) by following cylindrical plane (43).

Guard (23) has a clearance area indicated by (34) of 3661 mm that lies on plane (29).

The guard (23) has a clearance distance (35) of substantially 12.5 mm between clearance area (34) and inner wall (28) at all points within clearance area (34).

Guard Design and Exemplification

The inventors utilised a ‘learning first’ product development approach to develop guards (28, 36). Numerous prototypes were developed and tested to determine their ability to minimise or prevent force of an impact being transferred to greater trochanter (7 b). In particular, the inventors set out to develop guards that will ensure a force of 120 Joules or more does not cause an injury to greater trochanter and thereby prevent hip injury.

The results of the prototype tests have allowed inventors to develop the preferred embodiments of the guards (28, 36) as being effective and to achieve their intended goals. In addition, the testing of prototypes and variables helps to exemplify that the guards according to the present inventions are inventive.

Prototype and variable testing was completed using a model designed to comply with the International Hip Protection Research Group (IHPRG) testing standards.

A test rig was prepared proving a constant impact force of 3045N. A simulated greater trochanter and hip joint was provided to support various embodiments and prototypes of guards (23).

Force Attenuation

Table 3 shows the force attenuated by guards having a rigid body made from various materials, and in the case of Nylon with 30% glass fibre reinforcing also having liner in position. The guards used had a constant form as described through the anthro data with a variable step and clearance area.

TABLE 3 Impact Force = 3045N Nylon 30% PC ABS PP Acetal Nylon GF Attenuated 1504 1666 1816 1411 1760 1399 Force (N) Force 50.6 45.3 40.4 53.7 42.2 54.1 Reduction (%) Density 900- 900- 880- 1140- 1000- 1000- Range 1090 1030 1700 1540 1490 1490 (kg/m³) Ideal 1070 1020 890 1340 1120 1340 Density (kg/m³) Weight (g) 44.5 42.4 37.0 55.7 46.5 55.7 Combined 62.3 weight (EVA 30)

Table 4 shows force attenuated and as a percentage of total impact force for bodies made of different materials.

TABLE 4 Impact Force = 3045N Laminated EVA EVA EVA EVA PE PE 30/ 30 60 120 220 30 PE 140 Attenuated 1875 1880 1758 1650 1970 1798 Force (N) Force 38.4 38.3 42.3 45.8 35.3 41 Reduction (%) Weight of 6.6 13.1 26.2 48 6.6 40 Body (g)

The inventors investigated the affect of a foam layer across the footprint on attenuating impact. These tests used the preferred embodiment for the rigid body e.g. nylon containing 30% w/w glass reinforcing. The results of this testing is shown in Table 5.

TABLE 5 Impact Force = 3045 N EVA 30 EVA 45 Attenuated Force (N) 1372 1391 Attenuated Force (%) 54.9 54.3

Effect of Transitional Section on Impact Attenuation

The inventors investigated the affect of use of transitional section in rigid body on effectiveness of reducing or minimising transfer of force into greater trochanter. These tests were completed using a guard with a rigid body made from polycarbonate.

TABLE 6 Impact Force = 3045 N 5 mm Foot 10 mm Foot Attenuated Force N % N % No 2250 26.1 2170 28.7 Transitional section Transitional 1695 44.3 1670 45.2 section Difference 555 18.2 500 16.5

It can clearly be seen that use of a transitional section provided a significant increase in the amount of force attenuated by the tested guard.

However, it was found that guard made from polycarbonate materials did not perform well in repeated impact tests. This is believed to be due to polycarbonate having a low impact strength.

Clearance Distance

The inventors investigated the effect of clearance distance on the ability of a guard to minimise or prevent transfer of impact into greater trochanter. Results of the testing are shown in Table 7.

TABLE 7 Impact Force = 3045N EVA 30 EVA 60 EVA 120 EVA 220 Attenuated Force N % N % N % N % Without 2115 30.5 2085 31.5 1987

4.7 1935 36.5 Clearance Distance With 1875 38.4 1880 38.3 1758

2.3 1650 45.8 Clearance Distance Difference 240 7.9 205 6.8 229 7.6 285 9.3

indicates data missing or illegible when filed

It can clearly be seen that use of a minimum separation between greater trochanter and inner wall of cavity significantly reduces the size of an impact to contact the greater trochanter.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof. 

1-22. (canceled)
 23. A securing device configured to be worn by a person, comprising at least one pocket configured to receive a guard to provide protection to the person's greater trochanter, and a locking mechanism that is configured to alter the dimensions of the pocket to thereby facilitate selectively securing the guard at a plurality of positions relative to the securing device, wherein at least one of the plurality of positions corresponds to the person's greater trochanter so as to facilitate the guard protecting the greater trochanter.
 24. The securing device as claimed in claim 23, wherein the securing device is a pair of underwear to be worn by a person.
 25. The securing device as claimed in claim 23, wherein the locking mechanism is one or more pairs of complementary fasteners.
 26. The securing device as claimed in claim 25, wherein the locking mechanism includes at least three pairs of complementary fasteners.
 27. The securing device as claimed in claim 23, wherein the locking mechanism is configured to alter the length of the pocket.
 28. The securing device as claimed in claim 23, wherein the plurality of positions are spaced apart in the range of 70 mm-100 mm.
 29. The securing device as claimed in claim 28, wherein the plurality of positions are spaced apart in the range of substantially 90 mm.
 30. The securing device as claimed in claim 23, wherein the at least one pocket is positioned so as to lie adjacent against a person's greater trochanter when the securing device is being worn by the person.
 31. The securing device as claimed in claim 23, further comprising a second pocket that is configured to receive a second guard.
 32. The securing device as claimed in claim 31, further comprising a second locking mechanism to alter the dimensions of the second pocket to thereby facilitate selectively securing the second guard at a plurality of positions relative to the securing device.
 33. The securing device as claimed in claim 31, wherein the second locking mechanism is one or more pairs of complementary fasteners.
 34. The securing device as claimed in claim 33, wherein the locking mechanism includes at least three pairs of complementary fasteners.
 35. The securing device as claimed in claim 33, wherein the second locking mechanism is configured to alter the length of the second pocket.
 36. The securing device as claimed in claim 31, wherein the plurality of positions are spaced apart in the range of 70 mm-100 mm.
 37. The securing device as claimed in claim 36, wherein the plurality of positions are spaced apart in the range of substantially 90 mm.
 38. A method of securing a guard relative to a securing device as claimed in claim 23, the method comprising: (a) putting the securing device on a person; (b) selecting one of a plurality of positions at which to secure the guard; (c) positioning the guard at the position selected at (b); and (d) using the locking mechanism to secure the guard in the position selected at (b).
 39. The method as claimed in claim 38, further comprising: (e) forming a right angle between the person's thumb and first finger; and (f) laying the person's thumb on the iliac crest so that the palm of the person's hand; against the side of the leg thereby causing the person's first finger to sit approximately adjacent the person's greater trochanter sitting appropriately at the end of the person's middle finger.
 40. The method as claimed in claim 38, further comprising inserting the guard into the pocket.
 41. The method as claimed in claim 38, further comprising (b)-(f) so as to secure a second guard relative to the securing device.
 42. A kitset of parts, comprising: a guard to provide protection to a person's greater trochanter when in use, and a securing device as claimed in claim
 23. 43. The kitset as claimed in claim 42, further comprising a second guard.
 44. The kitset as claimed in claim 42, further comprising instructions on how to determine one of the plurality of positions at which to secure the guard to the securing device.
 45. The kitset of parts as claimed in claim 42, wherein the instructions teach a person to perform the steps of: (a) standing in an upright position; (b) forming a right angle between one's thumb and middle finger; (c) laying one's thumb on the iliac crest of the pelvis with the palm of one's hand laying against the side of the leg; and (d) identifying the hip bone as the boney protrusion sitting underneath approximately the end of one's middle finger.
 46. The kitset of parts as claimed in claim 45, wherein the instructions teach positioning the guard so as to lay overtop of the greater trochanter. 